We are now doing an epidemiologic case-control study funded by the National Institute of Child Health and Development in which we are examining the associations of socioeconomic status, social support, life stress, personal habits, and access to medical care with low birth weight. In the on-going study, the mothers of 400 low birth weight Black and 300 low birth weight White, singleton infants without congenital anomaly and the mothers of 400 "normal" weight Black and 300 "normal" weight White, singleton infants are being interviewed in their homes. We here propose to review the medical records of the approximately 30% of these subjects who delivered at a Kaiser facility hospital to determine the association of low birth weight with the earliness and adequacy of prenatal care, with its quality, and with three components of its content -- routine screening for bacteria, identification of smoking and counseling to stop, and identification of alcohol and/or substance abuse and counseling to stop. The study will resolve the question of whether better pregnancy outcome in women who have early and more prenatal care is due to the fact that these women have social and personal characteristics that are associated both with better outcome and with the seeking of prenatal care. An index of quality of prenatal care that can be used more widely will be developed. The specific association of overall quality and of three potentially important components of prenatal care with risk of low birth weight will be determined.